The present invention relates to a self-neutralising type of calcium hydroxide (Ca(OH)2) preparation for use in dentistry. More specifically, it relates to a self-neutralising type of calcium hydroxide preparation which is formulated in such a way that it can be used in dentistry by being mixed, in a cement clinker, with an active siliceous substance, bismuth oxide (Bi2O5), silica, sulphur trioxide and aluminum oxide/ferric oxide and the like. One aspect of the present invention provides a self-neutralising type of calcium hydroxide preparation comprising an active siliceous substance and bismuth oxide, and this self-neutralising type of calcium hydroxide preparation is characterized in that it comprises silica, sulphur trioxide and aluminum oxide/ferric oxide.
